1. Technical Field
The present invention relates to a method of determining mounting conditions of a mounter which mounts components onto a board, and in particular, to a method of determining mounting conditions which are adaptive to an individual mounter.
2. Background Art
Conventionally, both hardware and software solutions are provided in order to achieve higher throughput in a mounter which produces a component-mounted board by mounting electronic components onto a print wiring board or the like. The hardware solution aims at moving the components at a high speed in each of the following processes: a suction process of sucking and holding the components to be supplied to the board so as to pick up the components by vacuum; a transportation process of transporting the picked-up components from a component supply unit to the board; and a mounting process of lowering the transported components so as to place the components. The software solution aims to optimize mounting conditions such as an order of arranging component feeders for component supply which are equipped to the mounter, and an order of mounting the components (see reference to Japanese Laid-Open Patent Application No. 2002-50900).
In terms of hardware, tolerance of size is required in the manufacturing of the mounters, and variations in device accuracy among the individual mounters are generated due to varied manufacturing accuracies of the mounters even though the variations are within the range of the tolerance. Moreover, piece-to-piece variations in accuracy which are unique to an individual mounter such as a variation due to deterioration with age like wearing of the components making up a mounter and a variation due to change in temperature during the period from when the power is turned on until when the machine is warmed up.
Therefore, in terms of software, the mounting conditions which absorb the variations regarding hardware and guarantee a steady performance are set.
More precisely, (a) in FIG. 1 shows an ideal positional relationship between an electronic component A to be supplied and a suction nozzle 11 for sucking and holding the electronic component A. However, since there being diverse variations in the manufacturing of the mounters as mentioned above, the electronic component A may, in some cases, be supplied, misaligned with the ideal position as shown in (b) and (c) in FIG. 1. When the suction nozzle 11 attempts to suck and hold the supplied electronic component A and such misalignment occurs in the supply of the electronic component, the edge of the suction nozzle 11 is misaligned with the edge of the electronic component A.
Even in the conventional case where the edge of the suction nozzle 11 is misaligned with the edge of the electronic component A and the air leaks, as in the state shown in (b) in FIG. 1, it is still possible to directly transport the electronic component A and mount the electronic component A onto the board given that the static state is maintained for a certain period of time after the suction nozzle 11 come into contact with the electronic component A. Therefore, the variations with regard to hardware are absorbed by the software solution of setting mounting conditions which always include a static state lasting a certain period of time.
Thus, although many of the variations with regard to hardware are absorbed by the setting of the mounting conditions they are the factors that prevent the enhancement of the throughput of the mounter.
Note that the reason why the transportation and the mounting can be realized under the condition in which the static state is maintained despite of the leakage of the air is that the oscillation occurs due to the pressure within the suction nozzle 11 and the electronic component A to be sucked and held flutters immediately after the leakage, but when the static state is maintained for a certain period of time, it is possible to obtain the suction indicating a predetermined value or greater where the oscillation due to the pressure is settled down and its stability is restored. In the state as shown in (c) in FIG. 1, it is not possible to solve the problem by the software solution since the suction rate indicating a predetermined value or greater cannot be obtained even though the static state is maintained.
The present invention is conceived in view of the above-mentioned problem, and an object of the present invention is to provide the most suitable mounting conditions according to the state of an individual mounter in terms of hardware.